Elon Musk said Sunday that he plans to change the logo of Twitter to an “X” from the famous blue bird, marking what would be the latest big change since he bought the social media platform for $44 billion last year.

In a series of posts on his Twitter account starting just after 12 a.m. ET, Twitter’s owner said that he’s looking to make the change worldwide as soon as Monday.

“And soon we shall bid adieu to the twitter brand and, gradually, all the birds,” Musk wrote on his account. The change isn’t surprising given Musk’s long history with the name “X,” says Allen Adamson, co-founder of marketing consultancy Metaforce. The billionaire Tesla CEO tweeted last October that “buying Twitter is an accelerant to creating X, the everything app.”

Musk’s rocket company, Space Exploration Technologies Corp., is commonly known as SpaceX. And in 1999, Musk founded a startup called X.com, an online financial services company now known as PayPal.

“Not sure what subtle clues gave it way, but I like the letter X,” Musk tweeted Sunday.

But the change on Twitter was met with sharp criticism on the social media platform.

The change will be very confusing to a huge chunk of the Twitter’s audience, which has been already souring on the social platform given a slew of other major changes Musk has made, Adamson said.

“They won’t get it,” he said. “It’s a fitting end to a phenomenal unwinding of an iconic brand and business.”